Equations of Glomerular Filtration Rate and Biomarkers to Evaluate Renal Function: A Perspective

Early kidney disease is asymptomatic and strongly associated with morbidity and mortality, hence an accurate estimation of kidney function is crucial for its diagnosis. In turn, an appropriate diagnosis and treatment of chronic and acute kidney disease depends on early detection. Currently markers like blood concentrations of creatinine and Cystatin-C are used to estimate glomerular filtration rate, and others as proteinuria help to assess renal damage, but all of these have different limitations indicating the need for new biomarkers that can discriminate and detect damage, especially in the most critical situation during the development of kidney disease. Given that kidneys are the most important excretory organ, changes in blood concentration levels of a wide variety of metabolites can be a reflection of reduction of kidney function and renal damage. An ideal biomarker for renal disease has to be able to predict early diagnosis of kidney disease, allowing for identification of the type and etiology of the lesion, as well as initiation and monitoring of treatments. In this chapter, we describe the most relevant eGFR equation and biomarkers for kidney diseases.

Keywords: ADMA, AKI, BTP, CKD, Creatinine, Cystatin-C, FGF-23, GFR equations, IL-18, KIM-1, Kidney disease, L-FABP, Microalbumin, NAG, NGAL, Uric acid.